小天体自主附着多滑模面鲁棒制导方法研究

Study on Robust Multiple Sliding Surface Guidance Method for Autonomous Small Celestial Body Landing

小天体形状不规则及缺乏观测信息的特点使得小天体附近的动力学环境较为复杂,附着动力学模型存在较大不确定性。通过引入多滑模面鲁棒制导方法,分别设计2个滑模面,使探测器状态先后到达这2个滑模面,可实现指定时刻精确附着小天体的目标。通过选取参数的分析总结了制导律中相关参数的选取对燃料消耗的影响,给出了制导律相关参数选取原则。在存在外界环境扰动、初始状态误差和导航误差条件下,蒙特卡洛仿真结果表明:多滑面制导方法能够在小天体的不确知环境中实现高精度附着,且具有很好的鲁棒性。多滑模面制导方法精度高、鲁棒性好,且无需设计参考轨迹,实时性好,适合小天体自主精确附着的任务需求。

The irregularity of small celestial bodies and lack of observation data make the dynamical environment around them complicated,thus the landing dynamic model has relatively large uncertainty.Using robust multiple sliding surface guidance method that derives two sliding surfaces and makes the state of the lander reach the surfaces successively can achieve the goal of precise small celestial body landing.The impact of the guidance parameters on fuel consumption is shown through parameter analysis,and principles of parameterselection for the guidance law are given.Monte Carlo simulations considering external environment perturbations,initial state errors and navigation errors show that the multiple sliding surface guidance method can achieve precision landing in the uncertain environment of a small celestial body,demonstrating robustness.The multiple sliding surface guidance method has high precision and fine robustness,needs no reference trajectory,demonstrates good real-time performance,and thus matches the requirement of autonomous precision small celestial body landing.